On Tue, 11 Mar 2008 23:41:47 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article 47d6d912@qaanaaq,
Andy Hall wrote:
Glass if transparent is probably not a good idea. You have to have a
perfectbed of adhesive with no marks, blemishes or bubbles. Otherwise
the substrate shows straight through.

These had a sort of textured surface so probably not a problem. I didn't
much like them anyway.

They were probably woodchip.